Installation control valves

Claim 2

An installation control valve comprising: (a) a valve body for disposition in fire extinguishing installation pipework downstream of a pressurized source of extinguishant; (b) a butterfly valve disc within said valve body and normally retained closed to prevent the flow of extinguishant through the installation pipework, said valve disc being fixedly rotatably mounted within said valve body about an axis of rotation, that is off-set longitudinally of the point of intersection of a plane in which the periphery of said valve disc lies and a longitudinal axis of said disc normal to said plane by a distance sufficiently great that said valve disc will open with a slight pressure differential thereon and will close upon cessation of fluid flow, and said axis of rotation being parallel to said plane in all positions of said valve disc; (c) a movable stop cooperable with said butterfly valve disc and which in one position abuts said valve disc to retain said valve closed against pressure forces acting thereon and which in a second position frees said valve disc for pivotal movement; and (d) a retaining mechanism which is releasably held to resist stop movement and prevent said valve disc from opening, and which is operable under a predetermined condition to permit stop movement from said one position to said second position whereby unequal pressure forces on either side of the said off-set axis on one side of the valve disc can cause valve opening.

Claim 3

A valve as claimed in claim 1, in which said valve disc is rotatably mounted about an axis which is off-set both longitudinally and transversely of the point of intersection of said plane in which the periphery of the valve disc lies and said longitudinal axis of said disc.

Claim 4

A valve as claimed in claim 1, in which the valve disc is aerodynamically shaped.

Claim 5

A valve as claimed in claim 1, in which the valve disc is provided with means enabling the disc to open fully by creating a low pressure zone adjacent the downstream face of the disc.

Claim 6

A valve as claimed in claim 4, in which said means comprise baffle means.

Claim 7

A valve as claimed in claim 1, in which the valve disc cooperates with a sealing ring which is effective with pressure on both sides of the valve disc.

Claim 8

A valve as claimed in claim 1, in which the stop comprises a movable rod which passes to the exterior of a housing for the valve and is held in a valve disc abutment position by the retaining mechanism.

Claim 9

A valve as claimed in claim 7, in which the rod passes through an aperture defined by the housing, which aperture is sealed around the rod by a diaphragm peripherally clamped between the valve housing and a housing for the retaining mechanism.

Claim 10

A valve as claimed in claim 1, in which the retaining mechanism comprises a diaphragm arrangement which is adapted to be connected to a source of pressurised fluid.

Claim 11

A valve as claimed in claim 9, in which the stop comprises a movable rod which passes to the exterior of the housing for the valve and is connected to a diaphragm of the diaphragm arrangement and is resiliently biased by biasing means into said second position, which biasing means act, in use, against the pressure force of the fluid acting on the diaphragm.

Claim 12

A valve as claimed in claim 9, in which the movable stop may be held in said second position by a lever and cam mechanism acting on the diaphragm arrangement.

Claim 13

A valve as claimed in claim 1, in which a fluid discharge port is arranged in proximity to the valve disc whereby when the valve is closed the port is obturated and when the valve is open the port is open to permit a bleed of fluid to flow therethrough.

Claim 14

A valve as claimed in claim 12, in which the fluid discharge port is located in a projection which abuts the valve disc when it is in a closed position so obturating the discharge port and which additionally forms an immovable stop for the valve disc to prevent jamming of same.

Claim 15

A valve as claimed in claim 1, in which the retaining mechanism comprises an actuator such as a solenoid.

Claim 16

An installation control valve comprising: (a) a valve body for disposition in fire extinguishing installation pipework downstream of a pressurized source of extinguishant; (b) a butterfly valve disc within said valve body and normally retained closed to prevent the flow of extinguishant through the installation pipework, said valve disc being fixedly rotatably mounted within said valve body about an axis of rotation that is off-set longitudinally of the point of intersection of a plane in which the periphery of said valve disc lies and a longitudinal axis of said disc normal to said plane, and said axis of rotation being parallel to said plane in all positions of said valve disc; (c) a baffle extending across said valve disc on the downstream side thereof, said baffle having dimensions such that said valve disc opens fully under the pressure of fluid flow and remains open at low flow velocities; (d) a movable stop cooperable with said butterfly valve disc and which in one position abuts said valve disc to retain said valve closed against pressure forces acting thereon and which in a second position frees said valve disc for pivotal movement; and (e) a retaining mechanism which is releasably held to resist stop movement and prevent said valve disc from opening, and which is operable under a predetermined condition to permit stop movement from said one position to said second position whereby unequal pressure forces on either side of the said off-set axis on one side of the valve disc can cause valve opening.

Claim 17

An installation control valve comprising: (a) a valve body for disposition in fire extinguishing installation pipework downstream of a pressurized source of extinguishant; (b) a butterfly valve disc within said valve body and normally retained closed to prevent the flow of extinguishant through the installation pipework, said valve disc being fixedly rotatably mounted within said valve body about an axis of rotation that is off-set longitudinally of the point of intersection of a plane in which the periphery of said valve disc lies and a longitudinal axis of said disc normal to said plane, and said axis of rotation being parallel to said plane in all positions of said valve disc; (c) a baffle extending across said valve disc on the downstream side thereof, said baffle having dimensions such that said valve disc opens fully under the pressure of fluid flow and remains open at low flow velocities; (d) a movable stop cooperable with said butterfly valve disc and which in one position abuts said valve disc to retain said valve closed against pressure forces acting thereon and which in a second position frees said valve disc for pivotal movement; and (e) a retaining mechanism which is releasably held to resist stop movement and prevent said valve disc from opening, and which is operable under a predetermined condition to permit stop movement from said one position to said second position whereby unequal pressure forces on either side of the said off-set axis on one side of the valve disc can cause valve opening.

Claim 18

A valve as claimed in claim 15, in which said valve disc comprises bearing portions adapted for receiving spindles extending from said valve body wherein said valve disc in rotable about said axis upon said spindles, and in which said baffle comprises an upraised portion of said valve disc extending between said bearing portions and formed as a continuation of said bearing portions.

Claim 19

An installation control valve comprising: (a) a valve body for disposition in fire extinguishing installation pipework downstream of a pressurized source of extinguishant; (b) a butterfly valve disc within said valve body and normally retained closed to prevent the flow of extinguishant through the installation pipework, said valve disc being rotatably mounted within said valve body about an axis that is off-set longitudinally of the point of intersection of a plane in which the periphery of said valve disc lies and a longitudinal axis of said disc normal to said plane; (c) a movable stop cooperable with said butterfly valve disc and which in one position abuts said valve disc to retain said valve closed against pressure forces acting thereon and which in a second position frees said valves disc for pivotal movement; (d) a retaining mechanism which is releasably held to resist stop movement and prevent said valve disc from opening, and which is operable under a predetermined condition to permit stop movement from said one position to said second position whereby unequal pressure forces on either side of the said off-set axis on one side of the valve disc can cause valve opening; and (e) a projection extending inwardly from said valve body at a position so as to abut said valve disc opposite said movable stop to prevent said valve disc from jamming closed, a passage being formed through said projection and said valve body wherein said passage is closed in a closed position of said valve disc and communicated with the interior of said valve body in an open position of said valve disc to thereby provide to a point exterior to said valve body an indication of whether said valve is open or closed.

Claim 20

An installation control valve comprising: (a) a valve body for disposition in fire extinguishing installation pipework downstream of a pressurized source of extinguishant; (b) a butterfly valve disc within said valve body and normally retained closed to prevent the flow of extinguishant through the installation pipework, said valve disc being rotatably mounted within said valve body about an axis that is off-set longitudinally of the point of intersection of a plane in which the periphery of said valve disc lies and a longitudinal axis of said disc normal to said plane; (c) a movable stop cooperable with said butterfly valve disc and which in one position abuts said valve disc to retain said valve closed against pressure forces acting thereon and which in a second position frees said valves disc for pivotal movement; (d) a retaining mechanism which is releasably held to resist stop movement and prevent said valve disc from opening, and which is operable under a predetermined condition to permit stop movement from said one position to said second position whereby unequal pressure forces on either side of the said off-set axis on one side of the valve disc can cause valve opening; and (e) a projection extending inwardly from said valve body at a position so as to abut said valve disc opposite said movable stop to prevent said valve disc from jamming closed, a passage being formed through said projection and said valve body wherein said passage is closed in a closed position of said valve disc and communicated with the interior of said valve body in an open position of said valve disc to thereby provide to a point exterior to said valve body an indication of whether said valve is open or closed.

Claim 21

A valve as claimed in claim 17, in which said valve disc is provided with a sealing ring which closes said passage in said closed position of said valve.